Operating mechanism for domestic ironing machines and the like



Oct. 6, 1953 1 F. YOUNG 2,654,166

OPERATING MECHANISM FOR DOMESTIC IRONING MACHINES AND THE LIKE Filed Dec. 22, 1949 2 Sheecs-SheefI l I I \\V/l 4 z I I I I I I I I I I I II 6 I I I I I 3 IIII I II I 7 I I I II I I I z, I 5 II II I I 2 z v4 l II I .I II .r 1 I /I III II III II I w l I I 3 I I I 5 I II II III IIl III 5 /I I I 4 l :v

Inventor: James F Young, 10,5

l-Ie Attorhqg.

Oct 6, 1953 J. F. YOUNG OPERATING MECHANISM FOR DOMESTIC IRONING MACHINES AND THE LIKE 2 Sheets-Sheet 2 Filed Dec. 22, 1949 yI-Is Attorneb.

Patented Oct. 6, 1953 OPERATING MECHANISM FOR DOMESTIC IRONING MACHINES AND THE LIKE James F. Young, Bridgeport, Conn., assignor to General Electric Company, a corporation of New York Application December 22, 1949, Serial No. 134,473

5 Claims. 1

This invention relates to domestic ironing machines of the atplate type, and in particular to an improved mechanism for operating the pressing elements thereof in timed relation.

Domestic atplate ironing machines generally include a padded ironing table-known in the art as a buck-on which the articles to be ironed are laid by the operator; and a heated shoe which is carried on an arm structure pivoted relative to the buck to be brought into pressing position with relation thereto. By suitable mechanism the respective elements are then brought together to press the articles therebetween. A commercially popular ironing machine of this type is shown in the Wardwell, Jr. Patent No. 2,135,266 granted November l, 1938 for Ironing Machine. In the machine disclosed therein the shoe is moved manually, and as it approaches the ironing position switch means are automatically closed to energize a hydraulic motor system which drives the buck upwardly against the shoe.

My invention has for its main objectives the provision of improved means for automatically bringing both the shoe and the buck into ironing position; the provision of simple mechanical means for controlling the acceleration of the cooperating press elements; the provision of means for reducing extraneous forces on the buck operator as the shoe comes into operating position so as to make full pressure available for the ironing I operation; the provision of pressure operated valve means in the hydraulic motor system to govern the rate of rise and return of the pressing elements; and the provision of adjustable relief means to obtain substantially uniform operation U of the hydraulic motor system despite, for example, variations of viscosity of the liquid content of the system and subnormal line voltage available for operation of the motor.

In a presently preferred embodiment of my invention I accomplish these and other objects and advantages by associating operativelyV the hydraulic motor unit and the shoe carriage through a linkage system including camming means'arranged to produce variant rates of travel o-f the shoe carriage during its movement to operative position notwithstanding substantially uniform rate of operation of the motor unit. I have improved the iluid pressure generator element of the hydraulic motor unit by the provision of pressure operated valve members which establish one rate of pressure application against the piston of the motor as the shoe is rising, and relatively larger facilities and more rapid flow rate for the return flow of fluid so as to speed the return of the motor pistonand correspondingly the return movement of the shoe and buck-after the ironing operation. Such return is nevertheless accomplished smoothly because of the dashpot action of the piston and cylinder. The shape of the shoe carriage cam relieves the load on the motor as the shoe comes into position, and the buck accelerates its upward movement at the completion of its stroke.

In the accompanying drawing Fig. 1 is aside elevation of an ironing machine showing in full line the shoe and buck in retracted or "home position and in dotted line relative intermediate positions of these elements during their operation; Fig. 2 is a front elevation of the shoe drive linkage looking in the direction of the arrows 2 2 of Fig. 1; Figs. 3, 4, 5, and 6 are representative oi' the cam operation of the shoe linkage mechanism; Fig. 7 is a sectional side elevation of a hydraulic motor unit embodying the present invention, the section being taken on lines I-l of Fig. 8; and Fig. 8 is a top plan view of the piston head plate, Lshowing the pump cavity and valved outlet passages.

Referring now to Fig. 1, a domestic ironing machine of the flatplate type includes a frame structure I which is rarranged in the form of a table having a rigid top 2 on which is mountedA a cylinder 3 within which operates the hydraulic motor unit. As later explained, said unit carries the buck 4 and is arranged to drive said buck upwardly to exert ironing pressure against a heated shoe 5 which had previously come into operating position. The shoe is carried by a rigid, substantially U-shaped, carriage 6 pivotally supported on hangers 1 extending from the cylinder 3. Desirably said hangers are integral with the cylinder. The cylinder is provided with a flange structure 8 disposed at an angle relative to the cylinder axis so as to support the cylinder in an angular relation with respect to the table top, as viewed in side elevation. The lower portion of the cylinder projects through an opening provided in the table top. Generally speaking, said structure is not essentially different from that shown in the aforementioned Wardwell Patent No. 2,135,266. The 'shoe carriage may be cushioned at the extremities of its travel toward or away from the buck by suitable means such as the pairs of springs 9, I0 carried on rods II pivotallyafxed beneath the table top 2 at the sides of the cylinder 3. Suitable adjustment nuts I2, I-'I are provided to regulate the tension of the springs, which respectively bear against a bracket I5 slidably mounted on the respective rods I I.

Each bracket is pivotally attached to an arm i6 aixed to the carriage 6. It will be apparent that as the shoe arm rotates clockwise of Fig. l the spring 9 is compressed and that said spring may assist the return of the carriage. The spring Ill cushions the carriage at the end of its return movement; It should be understood that the buck and the shoe are elongate-and of' substantial area, and that each is symmetrical with respect to the cylinder 3.

I mechanically drive both.. thebuck.. and. the shoe carriage from the hydraulic. motor. device IZT disposed Within the cylinder 3. Broadly speaking, the motor unit comprises acombiziation pisfton and pressure generator whielr-pumps'iluitl to a space between the cylinder head and the piston head to drive the pistonwitbin thefcylinder. As shown in Fig 7, the unit has a piston-like structure I8 having a compartment in vflilichtis-V mounted an electric motor I9, to the shaft of which connected; ani impe-llerV 2b. operating; withm. a.v pump chamber 20m. of. doubie. involutef.` form. (seal-iig. 8.).. proyidedzby the respectiyewvalli members. 2i; 22:, .the latterfbeingtheactualpiston. head; The. Wall members 2'I, 2221V may bei bolted. together;` asv shown;Y and accommodate a. piston ring ML @ther Wali membersv disposed. interino.m diate-.thef ends. of; theepiston- Ie8- similarly; provide a seat for 'a piston ring 24. A cap 25 israiiixed to, the.A end-of the; piston, and:fixedl-y carries a trarne 2f.' having; outwardly'extendingmembers 2'1- on Whichthebuclrk isisuitably mounted.

eylinder'normally contains a, charge of. iiuid, .usually a; light mineral oil,v which occupies.r the cylincieitoa levelimmediately below the up-n per pistonring'ilanges; Theoii iss commun-icatiorr with. theimpellei'fpump chamberthrough thee apertures and the; pump' chamber inlet 2S.. When. ilieurrotor M31` is; energized;- as: by closingan. electric circuit;A inclini-ing.y a,- foot, pedal. actuated snritoliM 30,. the; impelle-r'. 2li. generates hydraulicy pressure: Whieh'isfdischargedinto a chamber` 3l: below thef pistmfirhead,y as presently explained The hydraulic pressure reacts against.V the pistoni head1 tof drive thestructui'e laupwardly. topizopel ablgef slotted; openings the upper Wal-l of; the,

cylinder 3;A 'Eovsaid--fends 3311 pivotally. aix the. linkmembers i4@ which in turn arei pivoted to an., arcuate yoke structure-3,55. secu-red relative-to the@ table-top 2 by. pivotal attachment. 45, tobrackets. .36." tl-iereon. Saidyoke isofcourse symmetrical.. with-.respectz tothe` piston structure t8.. A cross` bar, 3l offthe yoke extendssbeneath the shoe, oar-v. riage; 6 and-'carries a. roller 3& supported by the mounting'brackets 3S.. As. best appearsI inFig.. 2,` the lower. wall 4- of the carriage 6.v has an elongate openingl at. its extremity within whichv is; centered a. cam member. 4I- rigidlyI carried by the brackets 42. for engagement. by roller 38. Ad.- vantageously, and.V as. shownm Fig, 1Jl the end. 43, of the cam. may abut the topwall oi. the carriage 6. fonsecurement.thereto..

Inthe. operation oft. an ironingmachine, it. is. desirable that the shoe move rapidly during the iirst portionof ,its relatively long` movement. from the. retracted tov the operative. position but. that.

until the shoe comes into position the buck have a relatively short, slow movement. Not only does such relationship afford the operator an opportunity to perform any last instant smoothing of the article on the buck, but there is assured an adequate clearance between buck and shoe when ironing heavy articles, such, as' blankets or trousers. TheJ rate oil movementoi theshoef preferably lessens as the shoe approaches ironing position and the buck rate of rise desirably increases, Withminimumoextraneous load on the buck so that the. of motor force is applicable for the actual pressing operation. Such pattern oi movement maybe-accomplished with a simple, inexpensive construction by utilizing to advantage the chang-ing force application relationships. between :the-earn surfaces and the cam driving member as the shoe carriage moves from retracted. to pressing position, In the somewhat schematic cam representations of Figs. 3 and 6 it shouidi be noted". that. the` point M thereof cerrespondsatofthe pivot point ofb the carriage. 6, and-invEig; 6., .thepeint 45 represents the pif/tot: di. of yoke 35. 'i'heoam 4l: has; thel muti-,rallyV angularly associated surfaces 4'85, 41, 48Y along*V which the roller-'38s travels as the yoke 35,? is rotated; by. thev operation; of; the hydraulic motor unit l The motor piston moves. relatively slowlyl With-iinA the-cylinder, and correspondingly the. buck-rises; slow-ly, but. the angular vrelation ofithe cam' surface 5to the path of moi/ement off the roller: 38* issuch as: to translate thev pistonmoyement into. an immediaterelatively rapid rotation of the carriage-E; asv is: apparentv byrcomparison. of carriageV positions II-I and-IVYy otFig; 1', which correspond. to the-:cam representations eef. Figs., 31 and isv The. application of force of roller-,3E during. this.- phase is substantially normaltto the: cam surface. 45:, and; in viewoi,l the short lever arm betweenpivot M and. the poi-ntr of, enga-gement ofv roller 38 witlrt-he cam, thesmall'rise of the roller effects the illustrated, angular rotation of` the carriage 6.-. AtsFig. 5-the early relationship betweenthe arc of'move.- ment. of relier 3.8 and. the cam. surface Milf has? changed.,-l and the carriage movement becomes: less rapid, asfind-icated': by comparison of positions'IV and-.V of` Eig;- 1. There isza furthendeceleration as the rollerentersfupon cam facet 4i. Then as the roller 3.8. transfers from` surface 41 to: surface lathe-shoe movementbecomes relatively small, as indicated by the comparison of positions V and VI oi,` Eig... 1. As ay matter of` fact,- at Figi (iy the rollen .38 is; loing` verylii'ftlel Worlr on the:V carriage Bt'because-.z it will be notedthatthecam surface 4& makesa veryf small angle with the-arcuate. path of roller 3%. Therefore, betweenithe: positions V and. VI-theg shoe load has` practically been eliminated. from. the hydraulicy motor uni-t. 'I'hefnal movement of theshoeanditsca-rriage is aided by the shiftingr center oigravity ther-eci; the motor at this stag-e.. primarily concerned with compressingsprings so that. the reactionthere-1 owill. hold the. carriage securelyr aga-insti the roller 3,8... and, will provideV suiiicien-t. storage ci:7` forcesto throw. the. shoeA and. carriage rearwardly to an. oyercenter position-for. the return toretractedposition.

The movement. of. the motor un-it` H, Within. cylindery 3'is controlled by. valves awhich slid.- ably operate. in channels. 5l., formedin. plate 22. at.thefrespective.extremities vof the. involute-pump chamber. 20aV The plate: 2?,.isprovided with apertures of markedly different. diameter, the larger apertures4 52 being. atl the outermost ends oi the, grooves 5l so as to be actually externally of the pump chamber and the smaller apertures 53 being substantially at the entrance end of said grooves. Apertures 52 provide direct communication between chamber 3| and the liquid reservoir. The valve members 50 may comprise platelike elements in slidable engagement with the walls of the grooves and the bottom of plate 2| so as to have a substantially leak proof association with said walls, The spring members 54 bias the valves to occupy anormal position which exposes the openings 52 and covers openings 53. At the instant of operation of the impeller 20 therefore the hydraulic fluid has no escape from the impeller chamber and its first action is to drive the valve members 50 along channels 5| until the openings 53 are uncovered whereupon the hydraulic fluid enters the chamber 3|. The hydraulic unit drives upwardly at'the rate determined by the rate of flow of liquid through the discharge openings 53. The governing effect of the restrictions to impeller discharge provided by the openings 53 make the operation of the motor unit substantially uniform throughout a motor voltage range of from 90 to 130 volts. It should be understood that the openings 52 are closed by the valve members 50' when the latter have opened the ports 53 thus preventing any bypassing of hydraulic pressure through openings 52 to above the piston head. After the pressing operation has been completed the operator opens the switch 30 to de-energize motor I9 and the springs 54 drive the valve members 50 to expose the relatively large ports 52 and permit the weight of the buck to move the piston unit Il downwardly, oil returning to the cylinder above the piston head through said passages 52. Springs 9 keep the shoe carriage in'engagement with the cam roller 38 until the overcenter gravity position of the shoe and carriage is reached, following which such engagement is inherently maintained. The dashpot effect of the oil ports 52 is thus available to smooth the return movement of the shoe as well as the buck. The buck rises slowly during its initial movement, and ac celerates during its upward travel as the load imposed on the motor unit by the shoe and carriage becomes less.

It will be observed that with the releasable cam and roller arrangement of my invention the shoe carriage may manually be brought forward-for example, to position the shoe carriage for the use of the usual cover or enclosure (not shown) with which ironers of this type are usually provided.

Speed control of the buck and other operating advantages may be accomplished also by the inclusion of a pressure relief circuit in cylinder 3, arranging said circuit so that its downstream end enters the cylinder at a point coinciding with the up position of the shoe so that further motion of the piston will apply equal pressure to both sides of a pressure relief valve element to take the same effectively out of service. At this point, therefore, maximum fluid pressure will be available for the actual ironing operation. A suitable relief valve organization is shown in Fig. '7. A valve body 55 shaped to the curvature of the cylinder may be welded or otherwise secured thereto in leak-proof relationship. The valve body is bored to provide a flow circuit comprising the interconnected upstream and downstream legs 56, 51 which communicate with l the cylinder as shown. A sleeve 58 is fixed to the valve body in pressure tight relation therewith; said sleeve may be internally threaded to receive the valve stem guide member 60 withink which slidably operates a poppet type valve 6| biased by spring 62 into seated relation with respect to passage 56. By means of the suitably afxed adjustment knob 63 the member 60 may be rotated for movement axially within sleeve 58 so as to establish a desired spring bias against valve 6|.

It will be noted from Fig. 7 that with the piston in home position the upstream passage 56 is taken out of service by the respective piston elements 2| and 22. Initially therefore the fluid pressure is available at maximum level to overcome starting inertia of the operating elements. It has been noted that the cam drive of the shoe carriage effects maximum rotation of the carriage toward operating position during the very early stages of piston lift. Therefore by the time the upstream passage 56 is sufficiently cleared by the piston head to become operatively effective, the shoe carriage will have completed the greater portion of its travel. Therefore, by suitable 4adjustment of the valve bias, the operator may control the rate of movement of the buck and of the shoe during the nal drive to operating position. For example, by reducing the spring bias, a portion of the oil discharging through the ports 53 may be by-passed above the piston head thereby effectively slowing the piston drive. Conversely by increasing the spring bias one may appropriately reduce oil flow through the by-pass structure. In any event, it should be noted that if at any instant before the piston head assembly covers the downstream passage 51 abnormal restraint against the movement of the shoe carriage or buck develops-for example if the operator in an emergency sought to hold back the shoe while leaving switch 30 closed-the hydraulic pressure with the chamber 3| will be expanded in passage through the relief circuit and the ironer will not be exposed to damaging strains. After the piston has risen fully, at which time the shoe is in ironing position, the downstream port 51 is closed and the balance of pressure on each side of the valve 6| makes full pressure available against the piston head 22 for exertion of full ironing pressure.

While I have shown a particularembodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made; and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. In an ironing machine having a frame structure, a buck, a shoe, and a shoe carriage pivotally supported relative to said buck for movement between a retracted position with the shoe kremote from the buck and an operating position placing the shoe in register with the buck, the improvement in means for conjcintly propelling said buck and said shoe carriage into operative relationship comprising a motor unit including a cylinder fixed relative to said frame and pivotally carrying said shoe carriage, piston means within the cylinder and means for propelling the piston therein, said buck being secured to said piston, a yoke pivoted relative to said frame and extending into operative relationship with the shoe carriage, said yoke having an element in engagement with said carriage at a point spaced from its axis of rotation when said shoe 

